Method of making punches and dies



R. J. WILKIE METHOD OF MAKING PUNCHES AND DIES Filed Feb. 11, 1939Patented Clot. 3, 1939 anz'rnon or MAKING PUNCHES AND mus Robert J.Wilkie, Minneapolis, Minn, assignor to Continental Machine Specialties,Inc., Minneapolis, Minn., a corporation of Application Februaryll, 1939,Serial No. 255,893

7 Claims.

This invention relates to the art of making dies and refers particularlyto a method of making cutting and punching dies.

In the past, the matrix or die proper generally has been cut from apiece or blank of stock directly to or very close tothe outline of thedie layout line; and in the ordinary machining processes used for thispurpose, the part out out, which is sometimes called the slug, waseither reduced to chips or otherwise'rendered unfit for use. Thisresulted in considerable waste inasmuch as the punch for the die had tobe cut separately out of another piece of stock and very carefullymachined to fit the die proper.

This past method of making a set of dies (punch and matrix) was alsoobjectionable due to the excessive expenditure of labor necessary toproperly cut and fit the parts. v

This invention, therefore, has as one of its so objects the provision ofan improved method of making dies whereby the slug, which is thematerial cut from the blank in the roughing out of the die proper, maybe used to make the punch,

thereby effecting a considerable saving in time .and material, as asingle cutting operation roughs out the punch as well as the die properfrom a 1: single piece of material no larger t that *quired for the diepr *More specifically, this invention contemplates simultaneouslycutting the punch and die from a .sing'le'blank of material in such amanner that an excess of material -sufficient for properly finishing theedges of the punch and the die is left on both pieces. p p

" This invention also contemplates a method of cutting'th'e stripper forthe punch simultaneously with the cutting of the punch and the die. 3

With the above and other objects in view which will appearasthe'des'cription proceeds, this invention resides in'the novelconstruction, combinationand arr'angement'of parts substantially ashereinafter described and more particularly" defined by the appendedclaims, itibe'ing understood that such changes in .theprecise embodimentof the hereindisclo'sed .invention may be made as come within thescopeof the claims.

. The accompanying drawing; illustrates two complete examples of thephysical embodiment of 5 the invention constructed according to thebestmodes so far devised for the practicaluapplication of the principlesthereof, and in which:

Figure 1 is a perspective view partially in section, showing the mannerin which the cut is a made;

die and punch made in accordance with the meth od of this invention; Y

Figure 3 is a perspective view showing the punch and die directlyafterthe roughing operation with the slug (from which the punch ismade)removed from the die; and

Figure 2 is a vertical sectional view through a Figure 4 is a verticalsectional view illustrating a method of cutting a stripper-platesimultaneously with the cutting of the die.

Referring now more particularly to the accompanying drawing, inwhichlike numerals indicate like parts, the numeral 5 represents a block orblank of stock'of a size sufficiently large to be used as the matrix ordie proper. In order to cut the die so that the slug may be used as apunch, a hole 8 is first drilled through the thickness of the block atan angle to an axis normal to the general plane of the block. The angleat which the hole is drilled is sufllcient to dispose the edge of thehole at the top v face 1 of the block inside the die layout line 8 I andthe edge of the, hole at the bottom face 9 of theblock outside the dielayout line. The thickness of the stock thus determines the angle atwhich the hole is drilled and also the diameter of the hole, it beingdesirable to keep the hole as small as'possible. I I

After the hole has been drilled, a saw blade I ll is inserted throughthe hole. Any suitable type of power saw may beemployed; although it ispreferable to use a band saw (not. shown) in which case the blade mustbe cut and welded.

The table of the saw, representedby the line "1', is tilted so that thesaw blade passes through and substantially bisects the irregular planeconline at the'bottom'face 0 of'the block. The s des of the hole I I andof theslug l2 arefconsequently tapered, providing an excessof materialI! extending inside the die layoutline at the top face of the die, andan excess of material it at the'bottom of the slug i2 extending outsidethe die layoutline." a

After cutting, the slug i2 is removedas clearly illustrated in Figure 3.The edge ofthehole in the .matrix or dieproperfwhichjhasfthe excessmaterial I! overhanging the die layout line, is then accurately filedor'trimmed down to the to form the "land".

layout line perpendicularly to the face of the die The slug I2 istransformed into the punch by centering the die on the larger face ofthe slug and inscribing its contour thereon. The edge portion l4 outsidethe line thus obtained is then cut or filed off to form the straightside of the punch.

During the removal of the excess stock from the edge of the hole II andthe edge of the slug, the starting hole disappears from the straightside of the punch and the "land" on the die proper.

It is particularly significant that the slug or punch and the die properare cut simultaneously from a solid block. This assures greater strengthas the grain of the stock may be matched after finishing the punch anddie.

While it may be more feasible in most instances to use a saw for makingthe cut, it is understood that a cutting torch may be used, if desired.In this event, it is, of course, unnecessary to drill a starting hole.

If the shape of the punch and the die and the nature of the material tobe punched is such that a stripper is required, it may be producedsimultaneously with the roughing out of the punch and die. To this end,a plate i5 is secured to one side of the block 5, as shown in Figure 4.

A hole will then be cut in this plate to a shape corresponding with thatof the die layout line but sufliciently large to provide clearance forthe punch.

From the foregoing description taken in connection with the accompanyingdrawing, it will be readily apparent to those skilled in the art,

' that this method of making a die is particularly well suited whereverthe outline of the die is irregular and that a substantial saving inmaterial and time is efi'ected thereby.

What I claim as my invention is:

l. The herein described method of roughing out a punch and die from asingle piece of stock and in such a manner that the roughed out punchand die both have an excess of stock overhanging the die layout line,which comprises: forming a starting hole through a blank at an angle toan axis normal to the face of the blank and with the edge of the hole atone face of the blank inside the die layout line and the edge of thehole at the opposite face of the blank outside the die layout line;inserting a saw blade through said hole; and sawing through the blank atan angle to said axis with the saw-cut following the die layoutlineffand extending inside the boundary defined by the die layout lineat one face of the blank, and outside said boundary at the opposite faceof the blank-the .angle of sawing being different than that of thestarting hole whereby the hole is substantially eliminated at oppositesides during the sawing.

punch and the die so that the punch slugis movable through the hole inthe'die blank, said removal being such as to'provide the punch and thedie with clearance.

punch and die which comprises: drilling a hole through a die blank at anangle to an axis normal to the general plane. of the blank; inserting asaw blade through said hole; cutting a punch slug from the blank bysawing at an angle to said axis and in such relation to the die layoutline that the surfaces of the cut taper to provide an excess of materialoverhanging the die layout line at one face of the die and at one faceof the punch slug; and removing said excess material so that the punchslug is movable through the hole in the die blank.

4. The herein described method of making the male and female parts of adie which comprises: cutting a piece from a blank of material tosubstantially the size and shape of the male part of the die and withthe cut disposed at an angle to the face of the blank so that theperimeter of the piece at one of its surfaces is sufliciently largerthan its perimeter at its opposite surface to preclude passage of thepiece through the hole in the blank; and accurately removing part of theside walls of the piece and the hole to fit the piece to the hole forsmooth passage therethrough with the proper clearance for a punch anddie.

5. The herein described method of making a punch and die whichcomprises: cutting through a blank which is to form the diesubstantially along but spaced from the die layout line and at an angleto an axis normal to the face of the blank so that the area defined bythe cut and coinciding in size and shape with the area defined by thedie layout line lies on a plane between the faces of the blank and anexcess of stock overhangs the die layout line at one face of the piecethus cut from the blank and at one face of the blank; and removing saidexcess stock from both the blank and the piece to make the piece movablethrough the hole in the blank.

' 6. The herein described method of making a punch and die and astripper for the punch which comprises: removably securing a stripperblank to one side of a die blank; and simultaneously'cutting a holethrough said blanks with the surface of the cut tapered and the largestend of the hole in the stripper blank, and withthe cut so related to thedie layout line as to provide an excess of stock overhanging the dielayout line at one face of the die and at one face of the punch slug cutfrom the die blank and so that the hole in the stripper blank is largerthan the punch slug cut from the die blank.

7. The herein described method of making a punch and die whichcomprises: drilling a hole, through a die blank at an angle to an axisnormal to the general plane of the blank; inserting a saw blade throughsaid hole; cutting a punch slug from the blank by sawing at an angle tosaid axis less than the angle at which the hole is drilled and in suchrelation to the die layout line that the surfaces of the cut taper toprovide an excess of material overhanging the die layout line at oneface of the die and at one face of the punch slug; and removing saidexcess material so that the punch slug is movable through the-hole inthe die blank, the diiference in angularity between the drilled hole andthe saw cut being sufllcient to insure cutting away the drilled hole atthe cutting faces of the punch j sing and die blank during the removalof said "excess material. 3. The herein described method of maki aROBERT J. WILKIE.

